Ore-roaster.



G. H. BERN & T. P. HOLT.

OBE BOASTEB.. APPLICATION fILED APR. 9. 1914.

Patented Oct. 20, 1914.

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Specification o! Letters Patent..

Patent-ed Oct. 20, 191,4.

Appiicatioii sied pril e, i914.. sefiai no. 330,670.

' Be itllmown. that we, GnonGe'H. DERN sind THEoDoRn P. l-IoL'i, citizens of the United States, residing, respectively, at Salt Lake City;- county of Salt Lake, State of Utah, and `ark City, county of, Summit,- State of Utah, hiive invented certain .new and useful Imiprovenients in Ore-Roasters, of which the following is a specification.

This invention relates toblast oieroasters. Our Objectis the provision of @i 'novel ore roaster adapted for carrying out, ,the roasting process set forth in the applicationof Neils C. Christensen, Jr. and Theodore Pik Holt, filed August 3,1911, Serial No. 642,088

and that set forth in the patent to Wilhel Buddeus No, 1079897, dated November 25,

1913; and still further, adapted for. the performance of a blast roasting process ein bodying improvements on the roasting proeess of the said application and patent. Our invention'is adapted for the treatment of any metal bearing ore, particularly4 those ores which requirean oxidizing or chloridizing roast preparatory to the cxtracition ofthe valuable metals by any suitl able solvent. The invention relates,A more articularly to the provision of a novel bast roaste-r i adapted for the treatment of ores which are first finely crushed and, nioistened and (if not carrying the necessary fuel themselves) are mixed withsiiliicient fuel to adapt them for roasting by internal combustion of the mass, by forcing a blast of' air through the charge and for the treatment of the charge in a novel manner.

in the present invention we have provided :i hliist ore rooster en'ihodying improvements and novel features by which loss by volatilii zation, which in other .types of roosters when used for chloriflizingjr roasting is from ten to fifteen per cent., is practicallyY elimi noted; n saving of about seventy-five per centof the fuel consumed by other roastors is effected; the cost of installation is greatly minimized; thepfumes are controlled and,

when desired, inay'be easily condensed; the i roasted product is free from slime and con seqiiently mucheasier to leach; and dust-` ing, with-'its considerable loss, is entirely eliminated. Y -Our oije` roaster is vcontinuous in operation -to the extent that the fire is never allowed to go out and the roaster is never completely eii'iptie-d, although it is charged .and discharged intermittently; further, the

roasting zone is allowed to travel upward until it reaches the top of the charge, or substantially so,.ivhereupon it is dropped suddenly, after which it can again travel to the top. 7

A desideratuin in roasting wore. hyd-our p roccss is to ohvi:ite the occurrence of` portions or sections of the charge which offer less resistance than the remaining portions thereof, because such weak places' permit a, v

rush of air through them :ind thus the ore roasts more rapidly at these points than in other portions of the charge. lWe have `found 'that-a continuous' discharge of the roasted ore, as has been reviouslyproposei hasinvariably cracked tlie cake, or caused it to settle away from the wells of the roast-er, thereby forming air channels The present roosters-is adopted to cause the charge to drop quickly and freely at desired intervals, ind while 'cracks may occur, they may be scaled up with :i layer of fresh `o re and cause no difference in roasting. I

The present roaster maintains a permanent but shifting roasting zone in the co' liimnar charge of ore and removes thefroasted ore from beneath the roasting zone at in-v tervals, fresh iinroasted ore'being iidded on top es required.

Our invention consists, first, in the comhiiiation of an open veharge-supporting,'air

distributing, crushing grote composed of spaced rotatableor rocluble grate bars, a, chargeholding or roasting 4chamber -disposed thereztbove and in which the charge is supported by seid grate, sind an equa-lizing air pressure box or ciiiimber arranged below the gra-te and normally free from contained roasted ore, orl substantially so, but also incidentally serving as a hopper for the temporary Aholding of such portion of the charge ns is crushed and lowered byj the grate, until the discharged roasted iore may be removed; second, a novel. grate composed of rotatable or rockablejgrgite hars, operated byxsuitable means to rock!A or rotate, according t0 thev nature of' the ore which is undergoing treatment. y The grate bars are normally isietionary, but when the charge isVv to be dropped, they are set in operation and the teeth or rejections thereon disintegrate the bottoirirogthe roast4 'ed' cake and the entire ore mess Vis thereby quickly and evenly lowered without disturbing the relation of roasted ore particles to 

